Universal Persistent Brownian Motions in Confluent Tissues

TL;DR

This study shows that confluent tissues exhibit universal persistent Brownian motion in their long-term cellular dynamics, despite differences in active force mechanisms.

Contribution

It introduces a minimal framework for tissue dynamics based on persistent Brownian motion and distinguishes signatures of different active forces.

Findings

Long-time cellular motion converges to persistent Brownian dynamics.

Different active force modes produce distinct cell shapes and rearrangement statistics.

Persistent Brownian motion is a universal feature across active tissue models.

Abstract

Biological tissues are active materials whose non-equilibrium dynamics emerge from distinct cellular force-generating mechanisms. Using a two-dimensional active foam model, we compare the effects of traction forces and junctional tension fluctuations on confluent tissue dynamics. While these two modes of activity produce qualitatively different cell shapes, rearrangement statistics, and spatiotemporal correlations in fluid states, we find that the long-time cellular motion universally converges to persistent Brownian dynamics. This universal feature contrasts with the non-universal correlations between cell geometry, rearrangement rate, and fluidity, which depend sensitively on the underlying modes of active force. Our results demonstrate that persistent Brownian motion provides a minimal framework for describing tissue dynamics, while distinct active forces leave identifiable structural and dynamical signatures, thereby enabling inference of the dominant active force in fluid state tissues.